1. Field of the Invention The invention relates to cleaning heads for use in bottoms of swimming pools, and more particularly, to cleaning heads having nozzles which automatically rotate as water pressure is cycled on and off.
2. Description of the Prior Art
A variety of automatic pool cleaning systems have been devised to ease the task of keeping swimming pool surfaces free of settled debris. Some known systems utilize a plurality of "cleaning heads" disposed along bottom surfaces of swimming pools, the cleaning heads having nozzles which expell high velocity streams of water along the bottom surfaces of the pools to loosen settled debris from the bottom surfaces and mixing the debris with water immediately adjacent the pool surfaces. Such nozzles slowly rotate, so that the high velocity water streams radially rotate around the cleaning heads. The loosened debris can then be easily advanced toward a drain located in the deepest portion of the swimming pool and be drawn into a filtering system which removes the debris from the water.
One type of pool cleaning head of the type described above is disclosed in U.S. Pat. No. 3,408,006. However, that device is unduly large, complex, and expensive to manufacture. It includes a housing having two inner spaced rings of sawtooth-like teeth disposed along a cylindrical opening through the housing. A rotating head containing the nozzle has a pair of pins which extend outwardly into spaces between the teeth in the two rows. High pressure water forced into the cleaning head causes the rotating head and the pins to be raised. The pin engages sloped portions of the teeth of the upper row, causing the rotating head to rotate. When the water pressure is released, the head falls, causing the pins to engage sloped portion of teeth of the lower row, further rotating the rotating head and thereby further rotating the nozzle. As the water pressure is cycled on and off, the nozzle gradually rotates through a complete cycle. The device of U.S. Pat. No. 3,408,006 has a number of shortcomings; for example, it is 18" in height. The cost of providing receptacles in the bottom of a swimming pool to accommodate such large devices is unduly high. Further, since the entire rotating head is raised and lowered in response to cycling of water pressure, the device is unduly susceptible to inoperativeness caused by small rocks and other debris becoming stuck between the surrounding housing and the rotating head.
Accordingly, it is an object of the invention to provide a cleaning head having a very simple mechanism for rotating a high pressure water nozzle.
Another object of the invention is to provide a cleaning head which is substantially smaller than the cleaning heads of the prior art.
Still another object of the invention is to provide a swimming pool cleaning head which is not susceptible to having its operation interfered with by debris in a swimming pool.
Not only is the pool cleaning head disclosed in U.S. Pat. No. 3,408,006 unduly large and complex, its expense is increased by its difficulty of manufacture. The difficulty of manufacture results from the fact that it is not practical to produce the housing as a single unit by injection molding techniques because of the configuration of the above described two rings of teeth which must be formed within the housing. Hence, the housing must be formed from at least two injection molded parts which then must be fused or cemented together. Further, the stainless steel pins must be installed in the rotating head portion of the device so that the stainless steel pins extend between the space between the upper and lower rings of sawtooth-like teeth.
Accordingly, it is yet another object of the invention to provide a pool cleaning head system which can be manufactured and assembled without having to fuse or cement separately injection molded parts together.
Yet still another object of the invention is to provide a pool cleaning system which overcomes the above described shortcomings of the prior art.